The Outgrowth of Micrometastases Is Enabled by the Formation of Filopodium-like Protrusions

Disseminated cancer cells that have extravasated into the tissue parenchyma must interact productively with its extracellular matrix components to survive, proliferate, and form macroscopic metastases. The biochemical and cell biologic mechanisms enabling this interaction remain poorly understood. We find that the formation of elongated integrin β(1)-containing adhesion plaques by cancer cells that have extravasated into the lung parenchyma enables the proliferation of these cells via activation of focal adhesion kinase. These plaques originate in and appear only after the formation of filopodium-like protrusions (FLP) that harbor integrin β(1) along their shafts. The cytoskeleton-regulating proteins Rif and mDia2 contribute critically to the formation of these protrusions and thereby enable the proliferation of extravasated cancer cells. Hence, the formation of FLPs represents a critical rate-limiting step for the subsequent development of macroscopic metastases.     

Seroprevalence of West Nile virus and tick-borne encephalitis virus in southeastern Turkey: first evidence for tick-borne encephalitis virus infections

West Nile virus (WNV) and tick-borne encephalitis virus (TBEV) are among the medically important Flaviviruses that cause significant morbidity and mortality in humans. In this study, seroprevalence of WNV and TBEV in sera from two state medical hospitals from the southeastern part of Turkey was investigated. One hundred eighty-one serum samples were evaluated for WNV immunoglobulin G (IgG) by an indirect immunofluorescence test (IIFT) and for IgG antibodies against TBEV by a commercial enzyme-linked immunosorbent assay (ELISA) kit with enhanced sensitivity and specificity. Sera positive for WNV IgG were further analyzed by plaque reduction neutralization assay (PRNA). TBEV IgM was also investigated by ELISA in all seroreactive samples. Of 181 sera, 29 (16%) were positive for WNV IgG by IIFT and 17 of 179 (9.5%) were confirmed by PRNA. Nineteen of 181 (10.5%) sera were detected to have TBEV IgG. Mean titer of TBEV IgG was 43.0 RU/mL (median, 33.9 RU/mL; cutoff: 20 RU/mL). Four samples with WNV IgG antibodies were also positive for TBEV IgG antibodies. TBEV IgM was detected in 9 of 39 (23%) of all seroreactive sera, where IgM positivity were accompanied by IgG for 6 samples. These results suggest the presence of possible human WNV and TBEV infections in southeastern Turkey where vector activity have previously been detected.     

Clinical outcomes in "complex" thoracic aortic surgery

Although the term "complex aortic surgery" has come into increasing use, it has not been defined. We propose the following definition: replacement or remodeling (not resuspension of commissures) of the aortic root, together with either an intracardiac procedure or a replacement of more than 1 segment of aorta, all of which require cerebral protection. We retrospectively analyzed data pertaining to 152 patients (mean age, 56 +/- 12 years) who underwent surgery for thoracic aortic disease with aid of cardiopulmonary bypass from October 2000 through December 2005. The replaced segment was the ascending aorta with or without the root in 106 patients, the aortic arch in 15, and the descending aorta in 31. Among these patients, 10 met our proposed criteria and constituted the complex group. In this group, in addition to the aortic root, the entire thoracic aorta (ascending, arch, and descending) was replaced in 4 patients, the total arch in 2, and a partial arch in 1. The remaining 3 underwent valve or coarctation repair. Their outcomes were analyzed as a sub-group within the overall outcome. The in-hospital mortality rate was 12.5% in the overall group (19/152), 4.1% in elective cases (3/73), and 10% in the complex group (1/10). Duration of cardiopulmonary bypass, myocardial ischemia, and total cerebral protection times were significantly longer in the complex group (P <0.0001). Total cerebral protection time over 40 minutes was the only predictor of neurologic morbidity (P = 0.003; odds ratio, 4.7). Procedural complexity, as we defined it, increased neurologic morbidity, but not the mortality rate.     

Inferior vena caval tumor thrombus extending into the right atrium in a patient with pancreatic cancer

Venous thromboembolism is a common complication in patients with cancer and an important cause of morbidity and mortality. Idiopathic thrombosis, migratory or recurrent thrombophlebitis may be the first manifestation of an occult malignancy. While deep venous thrombosis and pulmonary embolism are the most common thrombotic conditions in patients with malignant disease, tumor thrombus may be seen in inferior vena cava, mainly in patients with renal cell carcinoma, hepatocellular carcinoma, testicular tumors or adrenal carcinoma. Although pancreatic cancer is one of the cancers that are most strongly associated with thrombotic complications along with cancers of ovary and brain, there has been no report about presence of thrombus in the inferior vena cava in pancreatic cancer. We report a female patient with pancreatic cancer associated with tumor thrombus extending from the inferior vena cava to the right atrium     

Gastric Tissue Oxidative Changes in Portal Hypertension and Cirrhosis

Gastric mucosal lesions are very common in portal hypertension and cirrhosis. The aim of this study was to assess for oxidative gastric tissue damage in cirrhosis and evaluate relations with portal hypertension and cirrhosis parameters. The study included 30 patients with cirrhosis and 30 controls. Each patient's history, physical examination, and laboratory findings were recorded, and multiple biopsies of the gastric antrum were obtained at endoscopy. A set of antral biopsies was also collected from each control subject. Each tissue specimen was analyzed for levels of glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) activity and level of malondialdehyde (MDA). Patients’ gastric GPX, SOD, and CAT levels were significantly lower, and MDA levels were higher, than in the control group. The GPX activity level in the specimens was moderately negatively correlated with portal vein diameter (P < 0.05, r=−0.45) and spleen length (P < 0.05, r=−0.45). In this study gastric tissue oxidative markers showed that antral oxidative factors worsen in cirrhosis. Oxidative stress may not be a clinical condition but it obviously shows gastric tissue damage and may explain many patients’ gastric lesions and hemorrhage.     

The Effects of N-Acetylcysteine on Bile Duct Ligation–Induced Liver Fibrosis in Rats

Stellate cells are activated by free radicals, and synthesize collagen. N-acetylcysteine (NAC) is a precursor of reduced glutathione and a potent scavenger of hydroxyl radicals and has potential antifibrotic effects. We aimed to test the effects of NAC on bile duct ligation (BDL) induced liver damage in rats. Forty-seven Wistar rats were divided into 5 groups: group 1, BDL + NAC (n = 10); group 2, BDL (n = 10); group 3, sham + NAC (n = 10); group 4, sham (n = 10); and group 5, control group (n = 10). NAC (50 μmol/kg per day) or saline of single doses were administered intraperitoneally for 28 days. Serum biochemical and liver oxidative stress parameters were studied. Liver collagen level was determined by the method of Lopez de Leon and Rojkind. Liver slides were stained by hematoxylin and eosin and Masson trichrome\Gomory reticulum staining. Aspartate aminotransferase (AST) and alkaline phosphatase levels in the BDL + NAC group were lower than the BDL group and were higher than the control groups (all P < .001). Malondialdehyde, luminal, and glutathione levels in group 1 were lower than the BDL group (P = .01, P = .002, and P < .001) and higher than the control groups (all P < .001). NAC had no effect on alanine aminotransferase (ALT), gammaglutamyl transferase, bilirubin, albumin, or lucigenin levels. Liver collagen levels were higher in the BDL groups (P < .001); however, NAC had no effect on the collagen levels. The BDL groups showed stage 3 fibrosis; all the control groups were normal. NAC improved some biochemical parameters (AST, alkaline phosphatase) and oxidative stress parameters (malondialdehyde, luminol, glutathione) in the BDL model. NAC was found to be effective on cholestasis-induced hepatotoxicity. However, NAC was inefficient as an antifibrotic agent within a 1-month period of administration in the BDL model.     

Canonical Correlation Analysis of Factors Involved in the Occurrence of Peptic Ulcers

The impact of risk factors on the development of peptic ulcers has been shown to vary among different populations. We sought to establish a correlation between these factors and their involvement in the occurrence of peptic ulcers for which a canonical correlation analysis was applied. We included 7,014 patient records (48.6% women, 18.4% duodenal ulcer [DU], 4.6% gastric ulcer [GU]) of those underwent upper gastroendoscopy for the last 5 years. The variables measured are endoscopic findings (DU, GU, antral gastritis, erosive gastritis, pangastritis, pyloric deformity, bulbar deformity, bleeding, atrophy, Barret esophagus and gastric polyp) and risk factors (age, gender, Helicobacter pylori infection, smoking, alcohol, and nonsteroidal anti-inflammatory drugs [NSAIDs] and aspirin intake). We found that DU had significant positive correlation with bulbar deformity (P=2.6×10^–23), pyloric deformity (P=2.6×10^–23), gender (P=2.6×10^–23), H. pylori (P=1.4×10^–15), bleeding (P=6.9×10^–15), smoking (P=1.4×10^–7), aspirin use (P=1.1×10^–4), alcohol intake (P=7.7×10^–4), and NSAIDs (P=.01). GU had a significantly positive correlation with pyloric deformity (P=1,6×10^–15), age (P=2.6×10^–14), bleeding (P=3.7×10^–8), gender (P=1.3×10^–7), aspirin use (P=1.1×10^–6), bulbar deformity (P=7.4×10^–4), alcohol intake (P=.03), smoking (P=.04), and Barret esophagus (P=.03). The level of significance was much higher in some variables with DU than with GU and the correlations with GU in spite of being highly significant the majority, were small in magnitude. In conclusion, Turkish patients with the following endoscopic findings bulbar deformity and pyloric deformity are high-risk patients for peptic ulcers with the risk of the occurrence of DU being higher than that of GU. Factors such as H. pylori, smoking, alcohol use, and NSAIDs use (listed in a decreasing manner) are risk factors that have significant impact on the occurrence of DU; aspirin has a significant impact on both DU and GU.     

Microfluidic system for on-chip high-throughput whole-animal sorting and screening at subcellular resolution

We report a suite of key microfluidic devices for complex high-throughput whole-animal genetic and drug screens. We demonstrate a high-speed microfluidic sorter that can isolate and immobilize Caenorhabditis elegans in a well defined geometry for screening phenotypic features at subcellular resolution in physiologically active animals. We show an integrated chip containing individually addressable screening-chamber devices for incubation and exposure of individual animals to biochemical compounds and high-resolution time-lapse imaging of many animals on a single chip without the need for anesthesia. We describe a design for delivery of compound libraries in standard multiwell plates to microfluidic devices and also for rapid dispensing of screened animals into multiwell plates. When used in various combinations, these devices will facilitate a variety of high-throughput assays using whole animals, including mutagenesis and RNAi and drug screens at subcellular resolution, as well as high-throughput high-precision manipulations such as femtosecond laser microsurgery for large-scale in vivo neural degeneration and regeneration studies.